This application claims the priority of German application 100 39 062.5, filed Aug. 10, 2000, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a transfer press and to an apparatus for loading and unloading workpieces.
DE 3336082 discloses a transfer press and shows divided gripper rails with grippers on the replaceable gripper rail sections, which can be turned up about a horizontal pivoting axis perpendicularly to the longitudinal extension of the gripper rails. The known construction can be used only for short transfer movements and relatively small workpieces and is not suitable for moving larger workpieces over a greater distance.
An object of the present invention is to provide an apparatus that obviates the above drawbacks and transports parts, including larger workpieces, very safely and reliably.
This object has been attained with an apparatus for loading and unloading workpieces, which has at least one essentially horizontally movable element, at least one essentially vertically movable element and at least one element for receiving workpieces.
An advantageous further development of the present invention provides that the horizontally movable element comprises at least one drive unit that produces the horizontal component of the movement. Still more advantageous are two drive elements because this increases operational safety since, even if one drive element fails, the entire apparatus can still be safely operated.
Another advantageous further development of the present invention provides that the horizontally movable element has at least two belts that communicate, respectively, with a drive unit and with the element for receiving the workpieces. These two drive belts increase the operating safety of the entire apparatus because safe operation is possible even with only a single belt.
Another advantageous further development provides that each belt is equipped with a belt lock. This increases not only the ease of operation and maintenance but also the operating safety and reliability of the apparatus.
An advantageous further development of the present invention provides that the horizontally movable element has at least one tension roller per belt. The tension roller(s) ensure(s) optimum belt tensioning at all times, so that optimum drive and friction conditions are present at any time of operation, and the degree of safety and reliability is further enhanced.
Another advantageous further development provides that the belts are linked by a bridge that is capable of limited deflection. This type of coupling of the two belts increases the degree of operating and production safety because, even if one drive belt fails, the other belt can maintain the function of the entire apparatus. Tests have shown that such an impaired drive is still capable of providing about two-thirds of the original output.
Another advantageous further development of the invention provides that the horizontally movable element has at least one guide. This guide or guides make it possible to achieve a highly reproducible transport result to enhance transport reliability.
An advantageous further development of the present invention provides that the horizontally movable element has at least one buffer for preventing damage in the event of malfunction. These stop buffers are suitable to prevent damage to the apparatus in case the apparatus ever accidentally leaves its planned path.
Still another advantageous further development provides that the vertically movable element has a safety brake, a motor and/or a spindle and/or a guide. This affords the advantage of increased operating safety even in vertical operation of the apparatus which is achieved by the individual elements.
Another object of the present invention has also been achieved by a transfer press with the loading and unloading apparatus that transmits the transfer movement to the workpieces. The transfer press here comprises the above-described apparatus for loading and unloading. The apparatus is freely programmable along the two axes (the y- and x-axis).